Fulminant immune-related colitis after dual checkpoint inhibitor therapy: case report

Area of Science:

• Oncology
• Immunology
• Gastroenterology

Background:

• Immune-related colitis (IR-colitis) is a serious side effect of immune checkpoint inhibitors (ICIs).
• Typical onset is 6-10 weeks post-immunotherapy initiation, presenting with diarrhea, abdominal pain, and rectal bleeding.
• ICIs, including anti-PD1 and anti-CTLA4, modulate the immune system to fight cancer, but can also trigger autoimmune responses.

Observation:

• We present a rare case of fulminant IR-colitis.
• Symptoms began unusually early, just 3 days after the first dose of dual checkpoint blockade (anti-PD1 and anti-CTLA4).
• The condition was refractory to high-dose corticosteroids and complicated by sigmoid diverticulum perforation.

Findings:

• Early-onset IR-colitis is possible, particularly with combined anti-PD1 and anti-CTLA4 therapy.
• Atypical timing of symptom onset does not exclude IR-colitis.
• Fulminant presentation and complications like perforation can occur.

Implications:

• Clinicians must maintain a high index of suspicion for IR-colitis, even with early or atypical symptom onset.
• Early diagnosis and management are crucial for potentially life-threatening IR-colitis.
• Further research is needed to identify risk factors for early-onset IR-colitis and optimize treatment strategies.